Interactions
Danthonia californica, or California oatgrass, is a native
species of grass, to California, that has a known tolerance for
frequent disturbances in its habitats. A grass that is tolerant
to disturbances such as fire, grazing, drought, and trampling
traffic (getting walked on) is what makes California oatgrass an
important asset to any garden or grassy meadow (Hayes and Holl
2011). Because of its persistent survival, California oatgrass
is widely used in restorations of upland prairies, oak savannas,
and transitional wetlands. The most important role of California
oatgrass is to enhance biodiversity of environments by providing
food for inhabitants, nesting areas, and hiding areas for gentle
creatures like butterflies, beetles, and songbirds (Darris and
Gonzalves 2008).
Grassy tarweed, the
popcorn flower, and the
Bottlebrush Squirreltail are all organisms that benefit from
California oatgrass being a resource within the same regions on the Pacific
Coast. California oatgrass can grow roots as long
as four feet long (Amme 2003) into the soil, this
deep penetration into the earth helps the grass find water even
during droughts. California oatgrass is high in nutrition and
is consumed for its grains by animals and birds, and for
its foliage by various insects. While the majority of California
oatgrass is needed for consumption, the grass has evolved to
grow long living
buds under the reach of grazing cattle, this
allows the grass to grow new foliage (Amme 2008). California
oatgrass grows in mesic grasslands, which are more fertile than
other types of grasslands, the high fertility is what allows for
the grasslands to accumulate a greater level of biomass. Because
mesic grasslands accumulate greater levels of biomasses, they
are susceptible to invasions by exotic grasses and shrubs.
Disturbance regimes like controlled fires and grazing are
actually needed to maintain this habitat. Invasive plants, NOT
adapted to grazing animals, are eaten and thus prevented from
invading and killing off native grass species that ARE adapted
to grazing animals and controlled fires (Hayes and Holl 2003).
The presence of grazing animals is extremely beneficial to the
oatgrass because it is not a competitive species of grass.
Specimens of California oatgrass have proven this in an
experiment conducted in 2008 by showing reductions in overall
growth while living in the presence of an invasive species of
grass (Pfeifer-Meister et. al 2008). The grass is
also a host for a species of nematode called "Cynipanguina
danthoniaea". The nematodes form a
symbiotic relationship with the oatgrass by living in tiny
spherical “galls” on the undersides of the grass’s blades for up
to two years.
Hosting the nematodes has not shown to be harmful to the health
of the oatgrass (Maggenti et al. 1973). In addition to hosting
nematodes, California oatgrass can also become the host of the
fungi Gloeotinia temulenta which causes "blind seed
disease" and can have a significant affect on surrounding
ryegrass. The blind seed disease can cause the germination rate
in seeds to drop to as low as 1% successful. Gloeotinia temulenta
is able to infect approximately 56 species world wide. The
fungus infects its hosts by releasing large numbers of
ascospores from its apothecia, typically at the same time of
year that ryegrass is flowering. Airborne spores can land on
stigmas, ovaries, or styles of flowers and will germinate and
infect its host. The fungus goes through a secondary infection
process where it "manifests" its host and fills it with a
pinkish slime that contains conidia spores. The conidia spores
are asexual and normally live for 1 month (Fischer 1944, Alderman 2001). California oatgrass
obtains water and nutrients by extending its fibrous root system three to four feet deep in
the surrounding soil
and absorbs any nutrients and water into its roots via
transpiration.
Help us finish our journey by learning some fun facts!